Medical lens assemblies and sterile drapes with a lens assembly

ABSTRACT

Medical lens assemblies and sterile drapes with a lens assembly are presented herein. In one embodiment, a lens assembly includes an annular lens housing that is attachable to a medical drape. The lens housing is configured to releasably attach to a medical device, such as a surgical microscope. An annular lens cover holder is removably attachable to the lens housing. A lens cover for shielding the objective lens is pivotably hinged to the lens cover holder. In another embodiment, a drape assembly includes a flexible body sized to cover an optical device. A lens housing attached to the drape body is engageable with the optical device to attach proximate an objective lens thereof. A lens cover holder is removably attached to the lens housing to rotate about a first axis. A lens cover is mounted to the lens cover holder to pivot about a second, different axis.

CLAIM OF PRIORITY AND CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.12/649,127, which was filed on Dec. 29, 2009, and is incorporated hereinby reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to optical devices requiring asterile field. More particularly, the present disclosure relates tomedical lens assemblies and sterile drapes with one or more lensassemblies for maintaining a sterile field.

BACKGROUND

During a surgical operation, the surgical site and surrounding areasmust remain sterile. A “surgical field” is an environmentally-controlledarea in a typical hospital operating room where the risk of infection,such as from naturally occurring organisms (e.g., bacteria), isminimized or eliminated. The sterility of the surgical field istypically controlled by limiting the introduction of infection-causingbacteria and other contaminants. In general, this is achieved byimplementing strict regulations over the personnel and equipment presentin the operating room.

Surgical drapes are often utilized during surgery in the operating roomto minimize the risk of infection to surgical patients and to protectmedical equipment from the surgical field. An array of differentsurgical drapes may be placed over the patient and the medical equipmentto create a sterile barrier, preventing microorganisms and othercontaminants that may cause infections from migrating to and fromexposed tissue, bodily fluids, etc. For example, bodily fluids secretedduring surgery that would otherwise settle on medical equipment, whichwould then become contaminated and potentially hazardous, will insteadultimately settle on the drapes and not on the draped medical equipment.

Optical devices, such as surgical microscopes and cameras, have becomean integral part of many operating rooms. Microscopes used for surgeryare generally permanent fixtures of the operating room, typicallymounted to the ceiling or a wall, or supported on a floor-mounted stand.Surgical microscopes often have an articulated cantilever supportarrangement to facilitate movement of the microscope over an operatingzone. Surgical microscopes normally take on very complex shapes, oftenhaving several sets of eyepieces that permit the surgeon and others tosimultaneously view the magnified area under the microscope's objectivelens. In addition to the ocular segments, one or more viewing tubesand/or laser arms (depending on design) project out from the microscopehousing.

Due to its complex geometry, it is very time consuming and difficult tothoroughly sterilize an entire microscope assembly before and after eachsurgical procedure. As such, it is common practice to cover themicroscope with a disposable surgical drape. The drape typicallycomprises a flexible sheet-form material that covers all of thecomponents of the surgical microscope, including the ocular ports, theviewing tubes, the microscope head, and the structure that supports thehead. The disposable surgical drape is typically manufactured andpackaged under sterile conditions so that, when unpackaged and placed ona microscope, the drape creates a sterile field around the microscopeand its components.

The microscope drape is often initially affixed to the microscope at thelens housing for the objective lens, to orient the drape with respect toother structure of the microscope. For example, some microscope drapesinclude an annular positioning sleeve that is attached to or integralwith an elongated tubular cover. The positioning sleeve fits onto theobjective lens housing of the microscope to initially affix the steriledrape to the microscope assembly. Once the surgical drape is attached tothe objective lens housing, the remaining portions of the drape can beconveniently unfolded and positioned to cover the remainder of themicroscope assembly.

In order to protect the objective lens without obstructing the view ofthe surgical area, a transparent protective lens (also referred to inthe art as “lens cover”) adapted to shield the objective lens is usuallyassociated with the drape assembly. For example, in some prior artconfigurations, a housing comprising a rigid mounting ring, whichencloses a transparent-plastic lens, is integrally-formed with thedrape. The mounting ring housing is adapted to attach, typically via aseparate adaptor or clamp, to the outer diameter of the microscopeobjective lens housing. Some designs incorporate an interchangeable lenscover that can be removed from the lens cover housing and replaced witha substitute lens cover.

Unlike typical microscopes, the illuminating light source of manysurgical microscopes comes from above and shines onto the lens covercovering the objective lens, which may generate glare when the surgeonlooks through the microscope. Moreover, during surgical operations, thelens cover can be splattered by fluids from the surgery, such as blood,which will obscure the surgeon's vision. To rectify this problem,someone on the surgical team is conventionally required to either wipethe lens cover (which can further obscure the vision), remove andreplace the lens cover (which requires a lens cover be taken fromanother drape assembly), or replace the entire drape (which temporarilybreaks the sterile field, is time consuming, and wastes another entiredrape assembly). Finally, different surgical microscopes use differentsize objective lenses. Thus, a facility with a variety of differentsurgical microscopes is required to carry an array of different surgicaldrape assemblies with lens housings and lens covers of various sizes,increasing overhead costs and unnecessarily complicating the preparationprocess for the operating room.

BRIEF DESCRIPTION OF THE DRAWINGS

Various advantages of the invention will become apparent upon readingthe following detailed description and upon reference to the drawings.

FIG. 1 is an exploded perspective-view illustration of a protective lensassembly in accordance with one embodiment of the present invention;

FIG. 2 is a cross-sectional side-view illustration of a sterile drapeassembly in accordance one embodiment of the present invention; and

FIG. 3 is a plan-view illustration of a lens cover holder in accordancewith one embodiment of the present invention.

While the invention is susceptible to various modifications andalternative forms, specific embodiments are shown by way of example inthe drawings and will be described in detail herein. It should beunderstood, however, that the invention is not intended to be limited tothe particular forms disclosed. Rather, the invention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the invention.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawings and will herein be described indetail representative embodiments of the invention with theunderstanding that the present disclosure is to be considered as anexemplification of the principles of the invention and is not intendedto limit the broad aspect of the invention to the embodimentsillustrated. To that extent, elements and limitations that aredisclosed, for example, in the Drawings, Abstract, and Description ofthe Illustrative Embodiments section, but not explicitly set forth inthe claims, should not be incorporated into the claims, singly orcollectively, by implication, inference or otherwise.

The present invention will be described herein in the context of asurgical lens assembly and a sterile surgical drape assembly forcovering a surgical microscope and creating a barrier between a sterilefield of an operating room and a surgical microscope. However, thepresent invention is by no means limited to this particular application.By way of non-limiting example, the concepts of the present inventionmay just as easily be incorporated into sterile drape assemblies used inany procedure requiring a sterile field, including surgical procedures,non-surgical medical procedures, and non-medical operations (e.g., in ascientific research clean room). Moreover, the lens assemblies and drapeassemblies of the present invention may be used on surgical microscopesand various other optical devices, such as medical imaging equipment(e.g., surgical cameras), operating room light fixtures, etc., withoutdeparting from the intended scope and spirit of the present invention.Finally, the drawings presented herein are not to scale and are providedpurely for instructional purposes. As such, absent explicit claimlanguage to the contrary, the individual and relative dimensions andorientations shown in the drawings are not to be considered limiting.

Referring to the drawings, wherein like reference numerals refer to likecomponents throughout the several views, FIG. 1 provides an explodedperspective-view illustration of an exemplary medical lens assembly,designated generally as 10, in accordance with various aspects of thepresent invention. The medical lens assembly 10 includes three primarycomponents: an annular lens housing 12, an annular lens cover holder 14,and a transparent, disc-shaped lens cover 16. Although depicted in FIG.1 as circular, donut-shaped (i.e., toroidal) components, the lenshousing 12 and lens cover holder 14 may take on additional shapes (e.g.,elliptical, polygonal, etc.), individually or collectively, depending onthe intended application and design requirements of the lens assembly10. Likewise, the lens cover 16 may take on additional geometricconfigurations without departing from the scope and spirit of thepresent invention.

The lens housing 12 is attached or attachable to a surgical drape 20 toform a drape assembly 18, as seen in FIG. 2. By way of example, the lenshousing 12 may be received in a complementary aperture 21 that is formedthrough a portion of the drape body 23. An adhesive may then be appliedto the outer periphery of the lens housing 12 along the interfacebetween the drape 20 and the lens housing 12, whereby the lens housing12, and thus the entire lens assembly 10 of FIG. 2, is coupled to thedrape 20. Alternatively, the lens housing 12 may be mechanicallyfastened to (e.g., via fasteners) or integrally formed with the drapebody 23.

According to one intended application, the drape assembly 18 of FIG. 2may be employed, as explained above, to create a physical barrierbetween a sterile field of an operating room and medical device,represented herein as a surgical microscope (shown hidden at 22 in FIG.2). In general, the microscope 22 includes an objective lens 24 that iscircumscribed by, and generally encased within a cylindrical objectivelens housing 26. The microscope 22 includes many other conventionalcomponents, such as a microscope body or main housing, one or moreeyepieces, a light source, etc. that are well known in the art. Sincethese components are well known in the art, and are per se not part ofthe subject invention, these structures will not be discussed orillustrated in detail herein.

The lens housing 12 is configured to engage with and thereby attach tothe medical device 22. In the illustrated embodiment, for example, theannular lens housing 12 comprises an outer backing ring, designated as28 in FIG. 1, with an inner-diameter surface 30 comprised of a flexiblematerial. According to one potential configuration, the outer ring 28 isfabricated from a rigid polymer, such as polypropylene, with anovermolded, soft thermoplastic-elastomer (TPE) forming theinner-diameter surface 30. Alternatively, other materials can be used,such as polyethylene, ABS, or any thermal plastic. The lens housing 12may be axially pressed or fed onto the outer surface of the objectivelens housing 26 of the surgical microscope 22. When circumscribing theobjective lens 24, the inner-diameter surface 30 of the lens housing 12compresses against and frictionally engages the outer-diameter surfaceof the objective lens housing 26, thereby attaching the drape assembly18, including the lens assembly 10 and drape body 23, to the surgicalmicroscope 22.

In the embodiment illustrated in FIG. 2, the lens housing 12 is providedwith a ramped surface 32 that extends continuously around a forwardinner-edge thereof. The ramped surface 32 acts as an angled alignmentfeature which facilitates engagement between the lens housing 12 andmicroscope 22 by properly orienting and axially aligning the lenshousing 12 with the objective lens housing 26 when being pressedtogether. The lens assembly 10 may be removed from the microscope 22 bypulling on or otherwise disengaging the lens housing 12 from theobjective lens housing 26. It is also envisioned that the lens assembly10, namely lens housing 12, be operatively coupled to the microscope 22by alternative means (e.g., via complementary helical threads,snap-fasteners, latches, adaptors, combinations thereof, etc.).

With continuing reference to FIG. 2, the inner-diameter surface 30 ofthe annular lens housing 12 may include an optional plurality ofcompliant protrusions 34 that project radially inwardly therefrom. Whenthe lens housing 12 is pressed onto the objective lens housing 26, thecompliant protrusions 34 compress or squeeze between the inner-diametersurface 30 of the lens housing 12 and the outer-diameter surface of theobjective lens housing 26, thereby increasing the frictional forcebetween the lens housing 12 and objective lens housing 26. Threeprotrusions 34 are illustrated in FIG. 2; however, more or fewer thanthree protrusions 34 may be incorporated into the lens housing 12design. This embodiment allows the inner-diameter surface 30 and theouter backing ring 28 to be molded and formed from the same material.

The surgical drape 20 is preferably made of materials now known orhereinafter developed that are commonly used in medical drapes. Suchmaterials may include, but are not limited to, coated papers andpretreated and/or pre-impregnated cloths, including non-woven and wovenfabrics, such as spunbond polypropylene (PPSB), spunlace, spunbondmeltblown spunbond (SMS), and combinations thereof. The drape materialmay also comprise bi-component non-woven materials, tri-laminates,bi-laminates, combinations thereof, and/or any variation of suchfabrics. The material may include hydro-entangled materials and otherfluid-resistant materials. However, one preferred material for thesurgical drape 20 is a clear plastic, such as polyethylene orpolyurethane, as the transparency eases application to the surgicalmicroscope 22. It is also possible for the plastic to be of a darkershade, while still being transparent, in order to reduce glare from thedrape itself. An “eco drape” type material is also envisioned for thesurgical drape 20, such as unbleached drape materials and/orfluorocarbon free drape materials that are biodegradable and/orcompostable.

The size and shape of the drape body 23 is sufficient to cover at leasta portion, but preferably all of the surgical microscope 22. Thegeometry and dimensions of the drape 20 may be varied depending uponfactors such as the size and design of the microscope 22 and otherpractical considerations. It is generally desirable that the drape 20 beprovided with the appropriate extensions and necessary openings thatcover and/or allow access to the various microscope oculars. The drape20 may also include optional strips of cloth or plastic (not shown),which allow the drape body 23 to be tightened and secured to themicroscope 22. For instance, plastic straps may be adhered or otherwisefixed at one end to an outer-side surface of the drape body 23, andprovided with adhesive on the opposite end such that the user can wrapthe straps around loose drape material, then secure the loose drapematerial to the microscope 22.

Referencing both FIGS. 1 and 2, the medical lens assembly 10 includes adisposable and/or interchangeable lens cover holder 14, wherein the lenscover holder 14 is easily attachable to and, in some embodiments,detachable from the lens housing 12. According to one exemplaryconfiguration, the lens housing 12 includes a circular flange 36 thatprotrudes radially outwardly from a bottom edge of the lens housing 12.In the illustrated embodiment, the flange 36 extends continuously aroundthe outer perimeter of the annular lens housing 12. Alternatively, thecircular flange 36 may be broken down into a plurality of individualsegments, each of which projects radially outwardly from the lenshousing 12.

Continuing with the above example, the lens cover holder 14 includes acomplementary arcuate slot 38 that is configured to receive and matewith the flange 36, thereby attaching the lens cover holder 14 to thelens housing 12. According to the embodiment illustrated in FIG. 1, forexample, the complementary arcuate slot 38 is a C-shaped channel thatprojects from the top surface of the lens cover holder 14. In thisexample, the arcuate slot 38 extends over approximately 180 degreesabout the upper surface of the annular lens cover holder 14, as bestseen in FIG. 3. In one preferred configuration, the arcuate slot 38extends over approximately 200 degrees, with a diameter of at leastabout 68 mm. To provide a more secure connection and eliminateinadvertent play between the lens housing 12 and the lens cover holder14, the inner diameter of the arcuate slot 38 is preferably the same as,or just larger than, the outer diameter of the flange 36, as seen inFIG. 2. Recognizably, in an alternate arrangement, the circular flange36 may project from the lens cover holder 14, whereas the complementaryarcuate slot 38 would be disposed on an appropriate surface of the lenshousing 12. In yet another alternate arrangement, it is also possiblethat the lens housing 12 and the lens cover holder 14 be fabricated asan inseparable, single-piece unitary structure.

In order to attach the lens cover holder 14 to the lens housing 12 (and,thus, the drape assembly 18 in the embodiment of FIG. 2), the lenshousing 12 and/or lens cover holder 14 are shifted or slid towards oneanother along a mutual lateral-plane—e.g., in a shearing-type motion.The flange 36 is pressed into the arcuate slot 38 until the lens housing12 and the lens cover holder 14 (and, thus, the flange 36 and slot 38)are generally concentric. Due to the length of the circular arc of thearcuate slot 38, the arcuate slot 38 acts to cup and retain the flange36 therein. The flange 36 and/or slot 38 may be fabricated from aflexible material to facilitate the flange 36 being press-fit intoengagement with the arcuate slot 38.

The lens cover holder 14 is selectively rotatable with respect to thelens housing 12 when operatively engaged therewith. That is, when theflange 36 is properly positioned inside the arcuate slot 38, the entirelens cover holder 14, including the lens cover 16, can be selectivelyrotated about a first axis A (FIG. 2) in both the clockwise andcounterclockwise direction without having to disengage the lens coverholder 14 from the lens housing 12 and/or the drape body 23. Asexplained below, the selective rotation of the lens cover holder 14 isin addition to, and independent of, the selective pivoting of the lenscover 16.

According to one advantageous facet of the present invention, the lenshousing 12 can be designed as a universal interface for attaching astandard-sized lens cover holder 14 to any of an array of differentmicroscopes with objective lenses of varying sizes. For instance,multiple versions of the lens housing 12 can be designed with anattachment flange 36 that has a common, predetermined outercircumference to mate with a standardized complementary arcuate slot 38of a predetermined diameter and geometric configuration. The innercircumference of the lens housing 12, however, can be adjusted toaccommodate (e.g., press-fit onto and frictionally engage)different-sized objective lens housings.

A universal lens cover holder 14 and lens cover 16, as taught herein,allows the end user to have a universal store of lens cover holdersseparate from a stock of surgical microscope drape assemblies. Thisfeature helps reduce overhead costs by eliminating the need to stockpilea variety of different replacement drape assemblies and/or replacementlens cover holders. This system also eliminates the need for a separatepermanent or semi-permanent adaptor attached to the objective lens.

Referring to FIGS. 2 and 3, the lens cover holder 14 secures the lenscover 16 at an angled position, shielding the objective lens 24 andseparating the microscope 22 from the sterile field. By way of example,the lens cover 16 is mounted, hinged or otherwise attached to the lenscover holder 14 such that the lens cover 16 can be selectively pivotedwith respect to the lens cover holder 14. As seen with reference to theembodiment illustrated in FIG. 2, the lens cover holder 14 includes aninternal chamber, designated generally at 40 in FIG. 2, within which thelens cover 16 is hingedly attached—e.g., via integrally-formed pivotarms 56 received in complementary holes 58 formed in the lens coverholder 14 (only one of which as visible in FIG. 1, but a second holebeing formed on an opposing side of the lens cover holder 14 to the oneshown). Alternatively, the lens cover 16 may be mounted on hinges thatare integrally-formed with the lens cover holder 14. The lens cover 16spans transversely across the internal chamber 40 of the lens coverholder 14, effectively blocking the path between longitudinally offsetopenings 42 and 44 of the lens cover holder 14.

The lens cover 16 pivots about a second axis B that is different fromthe first axis about which the lens cover holder 14 rotates, as seenwith comparative reference to FIGS. 2 and 3. In one particular facet,the second axis B is generally orthogonal with respect to the first axisA. The lens cover pivot axis B, for example, may be oriented generallytransversely with respect to the longitudinal axis of the annular lenscover holder 14; the lens cover holder axis of rotation A beingcoaxially aligned with the longitudinal axis of the lens cover holder14. Likewise, as seen in FIG. 2, the first axis A may be generallycoaxially oriented with respect to the viewing axis (i.e., thelongitudinal axis) of the objective lens 24, whereas the second axis Bmay be generally transverse with respect to the viewing axis of theobjective lens 24. The angular and planar offset between the lens coverhousing 14 axis of rotation A and the lens cover 16 axis of pivot B maybe varied depending upon such factors as the intended application,design requirements, and other practical concerns relating the lensassembly 10 and drape assembly 18. To that end, the lens cover 16 pivotangle ø, FIG. 2, which is preferably at least about 20 degrees, may bemodified as required. An optional tilt knob 54 may be operativelyattached to or integrally formed with the lens cover 16, providing theuser a mechanical interface for selectively pivoting the lens cover 16.

The internal chamber 40 illustrated in FIGS. 1 and 2 is a butterflychamber, with first and second semi-circular, wedge-shaped sections 46and 48, respectively. In other words, each section 46, 48 is shown inFIGS. 1 and 2 as an approximately 20° truncated-segment of a sphere witha radius that is generally coextensive with the radius of the lens cover16. The first wedge-shaped section 46 nests a first-half of the circularlens cover 18, whereas the second wedge-shaped section 48 nests asecond-half of the circular lens cover 18. The internal chamber 40 ofthe lens cover holder 14 also includes first and second angularly offsetshoulders 50 and 52, respectively. The shoulders 50, 52 cooperate tolimit the range of pivoting of the lens cover 16 by obstructing therotational path of the lens cover 16. By way of clarification, when thelens cover 16 reaches a predetermined angular threshold (e.g., 20° inFIG. 2), each shoulder 50, 52 will press against a respective opposingportion of the lens cover 16, restricting the lens cover 16 fromtransitioning any further.

In the embodiment shown, the lens cover 16 is shown as a thin, flat,circular lens that is fabricated from a transparent orgenerally-transparent material, such as polycarbonate. The lens cover 16may be coated or laminated with anti-glare or anti-fog materials. Thelens cover holder 14, on the other hand, is a generally-rigid, opaquematerial, such as polypropylene, that may colored black or othercomparable pigments. The pivotable lens cover 16 described hereinabovedeflects unwanted glare away from the ocular path and allows the enduser to re-direct the glare to whatever direction he/she desires. Inembodiments where the lens cover 16 is not curved, distortion of theoriginal microscope vision is further minimized. Also, by coloring thelens cover housing (e.g., black), the amount of light being reflectedback to the lens cover 16 is minimized.

The medical lens assembly 10 described hereinabove allows for thereplacement of only the removable lens cover holder 14 when the lenscover 16 is obscured by fluids. This eliminates requiring the user towaste an entire, new drape assembly to find a replacement for the lenscover. This particular facet of the present invention also eliminatesthe necessity of having to operate without a lens cover or having towipe the lens cover, thus potentially obscuring visual clarity. Inaddition, the lens cover holder is removed and attached horizontally,decreasing the chance of the lens cover dropping into the surgical siteduring removal or attachment. The lens cover holder also attaches to thelens housing without telescoping, thus preserving the visual scope ofthe microscope.

Exemplary Alternate Embodiments

The following exemplary embodiments of the invention are not intended torepresent each embodiment, or every aspect, of the present invention.The above features and advantages, and other features and advantages ofthe present invention, will become more readily apparent from thefollowing description.

According to one embodiment of the present invention, a lens assemblyfor a medical drape is featured. The lens assembly comprises an annularlens housing that is attachable (e.g., via adhesives) to the medicaldrape. The lens housing is configured to engage with and thereby attachto the medical device. An annular lens cover holder is removablyattachable to the lens housing. The lens assembly also includes a lenscover that is configured to shield the objective lens. The lens cover ishinged to the lens cover holder such that the lens cover is selectivelypivotable with respect to the lens cover holder.

In accordance with one optional facet of the present invention, the lenscover holder has an internal chamber within which the lens cover pivots.Optionally, the internal chamber of the lens cover holder includes firstand second angularly offset shoulders. Each shoulder presses against arespective portion of the lens cover to thereby restrict the pivot angleof the lens cover.

In accordance with another optional facet, the lens cover pivots aboutan axis that is generally transverse with respect to a longitudinal axisof the annular lens cover holder. It may be desirable that the lenscover be able to pivot at least 20 degrees. To that end, the lens covermay be provided with a tilt knob for selectively pivoting the lenscover.

As part of another optional facet of the present invention, the lenshousing or the lens cover holder includes a flange that protrudestherefrom. Optionally, the flange extends around an outer perimeter ofthe annular lens housing or the annular lens cover holder. The other ofthe lens housing and the lens cover holder includes a complementaryarcuate slot that receives the flange, thereby attaching the lens coverholder to the lens housing. Optionally, the arcuate slot extends over180 degrees about an upper surface of the annular lens housing orannular lens cover holder. The flange may be fabricated from a flexiblematerial such that the flange can be press-fit into engagement with thearcuate slot.

According to yet another aspect, the annular lens housing has aninner-diameter surface comprised of a flexible material. The flexiblematerial allows the inner-diameter surface to frictionally engage withan outer-diameter surface of an objective lens housing and therebyattach the lens housing to the medical device. Additionally, or as analternative thereto, the inner-diameter surface of the annular lenshousing may be provided with a plurality of compliant protrusions thatproject inward therefrom. The protrusions engage with the outer-diametersurface of the objective lens housing to provide additional/alternativemeans for attaching the lens housing to the medical device.

As part of yet another aspect of the present invention, the lens housingand lens cover holder both have a common, fixed outer diameter, whicheliminates the possibility of the lens cover holder and lens housingfrom telescoping with respect to one another. In contrast, the innerdiameter of the lens housing may be selectively modifiable toaccommodate objective lens housings of varying outer diameters. Thisoptional configuration provides for a universal lens cover holder thatis interchangeable with an array of lens housings that accommodateobjective lens housings of varying sizes.

According to another embodiment of the present invention, a drapeassembly is provided for creating a barrier between a sterile field andan optical device, such as a surgical microscope or camera. In thisembodiment, the drape assembly includes a drape body comprising aflexible material sized to cover at least a portion of the opticaldevice. A lens housing, which is attached to the drape body, isengageable with the optical device to attach thereto proximate to theobjective lens of the optical device. The drape assembly also includes alens cover holder that is removably attached to the lens housing torotate about a first axis. A lens cover is mounted to the lens coverholder to pivot about a second axis that is different from the firstaxis.

In accordance with one optional facet of the present invention, thesecond axis is generally orthogonal with respect to the first axis.

As part of another optional aspect, a flange protrudes laterally from abottom edge of the lens housing. In this instance, a complementaryC-shaped slot projects upwardly from a top surface of the lens coverholder. The C-shaped slot is configured to receive the flange andthereby attach the lens cover holder to the lens housing. Ideally, theC-shaped slot extends over 180 degrees about the top surface of the lenscover holder.

According to another optional facet, the lens cover holder defines aninternal chamber. The lens cover is positioned inside and spans acrossthe internal chamber of the lens cover holder. The internal chamber ofthe lens cover holder may be provided with angularly offset shoulders,each of which is configured to obstruct the movement of the lens coverand thereby limit the pivoting range of the lens cover.

In accordance with yet another embodiment of the invention, a surgicaldrape assembly is presented for creating a barrier between a sterilefield of an operating room and a surgical microscope. In thisembodiment, the surgical drape assembly includes a drape body comprisinga sheet-like material sized to cover substantially all of the surgicalmicroscope. An annular lens housing is fixed to the drape body. The lenshousing is configured to press-fit onto an annular objective lenshousing of the surgical microscope, whereby the drape body is removablyattached to the surgical microscope. An annular lens cover holder withan internal chamber is removably mounted to the lens housing to rotateabout a first axis that is generally coaxial with a viewing axis of themicroscope's objective lens. The surgical drape assembly also includes asubstantially-transparent lens cover that is positioned inside and spansacross the internal chamber of the lens cover holder. The lens cover ishinged to the lens cover holder to pivot about a second axis that isgenerally transverse with respect to the viewing axis of the objectivelens.

While the present invention has been described with reference to one ormore particular embodiments, those skilled in the art will recognizethat many changes may be made thereto without departing from the spiritand scope of the present invention. Each of these embodiments andobvious variations thereof is contemplated as falling within the spiritand scope of the invention, which is set forth in the following claims.

1-20. (canceled)
 21. A lens assembly for a drape adapted to cover atleast a portion of an optical device having an objective lens, the lensassembly comprising: a lens cover configured to shield the objectivelens; a lens cover holder attached to the lens cover; and a lens housingconfigured to attach to the drape, the lens housing being furtherconfigured to engage with and thereby attach to the optical device,wherein one of the lens housing and the lens cover holder includes acircular flange protruding therefrom, and the other of the lens housingand the lens cover holder includes a complementary C-shaped arcuate slotreceiving therein the circular flange and thereby removably attachingthe lens cover holder to the lens housing.
 22. The lens assembly ofclaim 21, wherein the circular flange extends continuously around aperimeter of one of the lens housing and the lens cover holder, andwherein the C-shaped arcuate slot extends over 180 degrees, but lessthan 360 degrees, along a perimeter of the other of the lens housing andthe lens cover holder.
 23. The lens assembly of claim 22, wherein thecircular flange projects radially outward from the lens housing, and theC-shaped arcuate slot projects from the lens cover holder.
 24. The lensassembly of claim 22, wherein the C-shaped arcuate slot extends over 200degrees along the perimeter of the other of the lens housing and thelens cover holder.
 25. The lens assembly of claim 21, wherein thecircular flange is positioned inside the C-shaped arcuate slot bysliding the lens housing or the lens cover holder, or both, towards oneanother along a mutual lateral-plane in a shearing-type motion.
 26. Thelens assembly of claim 21, wherein the circular flange is fabricatedfrom a rigid polymeric material and the C-shaped arcuate slot isfabricated from a flexible polymeric material such that the circularflange is press-fit into engagement with the C-shaped arcuate slot. 27.The lens assembly of claim 21, wherein the lens cover holder and thelens housing are both annular and concentrically aligned along a commonlongitudinal axis when attached.
 28. The lens assembly of claim 21,wherein the lens cover holder defines an internal chamber, the lenscover being positioned inside and spanning across the internal chamberof the lens cover holder.
 29. The lens assembly of claim 28, wherein theinternal chamber of the lens cover holder includes opposing first andsecond semi-circular, wedge-shaped sections each of which receivestherein a respective portion of the lens cover.
 30. The lens assembly ofclaim 21, wherein positioning the circular flange inside the C-shapedarcuate slot allows the lens cover holder to rotate about a first axis,and wherein the lens cover is pivotably attached to the lens coverholder to pivot about a second axis extending generally transverse withrespect to the first axis.
 31. The lens assembly of claim 30, whereinthe second axis of the lens cover is generally orthogonal with respectto the first axis of the lens cover holder.
 32. The lens assembly ofclaim 21, wherein the lens housing is annular and comprises an outerbacking ring fabricated from a rigid polymer and an inner-diametersurface fabricated from a flexible polymer, the lens housing beingconfigured to be pressed onto an objective lens housing of the opticaldevice such that the inner-diameter surface of the lens housingcompresses against and frictionally engages an outer surface of theobjective lens housing.
 33. A drape assembly for covering at least aportion of an optical device, the optical device having an objectivelens housed in an objective lens housing, the drape assembly comprising:a flexible drape body sized to cover at least a portion of the opticaldevice; a lens housing attached to the flexible drape body, the lenshousing being configured to engage with the objective lens housing andthereby removably attach the drape assembly to the optical device; alens cover holder defining an internal chamber; and a transparent orsubstantially transparent lens cover positioned inside and spanningacross the internal chamber of the lens cover holder, wherein one of thelens housing and the lens cover holder includes a circular flangeprotruding therefrom, and the other of the lens housing and the lenscover holder includes a complementary C-shaped arcuate slot receivingtherein the circular flange and thereby removably attaching the lenscover holder to the lens housing.
 34. A method of assembling a drapeassembly for covering an optical device having an objective lens, themethod comprising: providing a transparent or substantially transparentlens cover configured to shield the objective lens; providing a lenscover holder; attaching the lens cover to the lens cover holder;providing a lens housing configured to engage with and thereby attach tothe optical device proximate the objective lens; attaching the lenshousing to a drape body; and attaching the lens cover holder to the lenshousing, wherein one of the lens housing and the lens cover holderincludes a circular flange protruding therefrom, and the other of thelens housing and the lens cover holder includes a complementary C-shapedarcuate slot receiving therein the circular flange and thereby attachingthe lens cover holder to the lens housing.
 35. The method of claim 34,wherein the circular flange extends continuously around a perimeter ofone of the lens housing and the lens cover holder, and wherein theC-shaped arcuate slot extends over 180 degrees, but less than 360degrees, along a perimeter of the other of the lens housing and the lenscover holder.
 36. The method of claim 34, wherein the circular flangeprojects radially outward from a bottom edge of the lens housing, andthe C-shaped arcuate slot projects upwardly from the top surface of thelens cover holder.
 37. The method of claim 34, wherein the C-shapedarcuate slot extends over 200 degrees along a perimeter of the other ofthe lens housing and the lens cover holder.
 38. The method of claim 34,wherein the circular flange is positioned inside the C-shaped arcuateslot by sliding the lens housing or the lens cover holder, or both,towards one another along a mutual lateral-plane in a shearing-typemotion.
 39. The method of claim 34, wherein the circular flange isfabricated from a rigid polymeric material and the C-shaped arcuate slotis fabricated from a flexible polymeric material such that the circularflange is press-fit into engagement with the C-shaped arcuate slot. 40.The method of claim 34, wherein positioning the circular flange insidethe C-shaped arcuate slot allows the lens cover holder to rotate about afirst axis, and wherein the lens cover is pivotably attached to the lenscover holder to pivot about a second axis extending generally transversewith respect to the first axis.